An intelligence unit under the South Korean Defense Ministry reportedly orchestrated the mass defection of 13 North Korean restaurant workers based in China in 2016.

A source familiar with the case said Tuesday that the defection was led by the Republic of Korea Defense Intelligence Command(KDIC) in the initial stage and the National Intelligence Service(NIS) came to be involved in the case after the North Koreans arrived in Shanghai to enter South Korea.

The claim runs against a statement by Ho Kang-il, the North Korean manager of the restaurant in the Chinese port city of Ningbo, who defected to South Korea together with the 12 female workers in April 2016.

Ho told Yonhap News on Sunday that the NIS orchestrated the group defection, saying that the spy agency had lured him into defecting by promising to help him obtain South Korean citizenship and run a restaurant in Southeast Asia.

However, the source said that the KDIC was behind the plan in the initial stage, encouraging the manager to leave the restaurant along with the employees and transporting them to Shanghai.

The source added that the spy agency was involved in the process in which the North Koreans escaped Shanghai to enter South Korea via a third country.